Write a durable note (<= 8192 characters). Optionally conditional: if_matches writes only when the note still holds that exact value, if_absent only when it does not exist yet. A failed condition reports the value that is actually there.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | Note key. | |
| value | Yes | Note body, <= 8192 characters. | |
| if_absent | No | Create-only guard. | |
| namespace | Yes | Note namespace. | |
| if_matches | No | Compare-and-set guard. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark this as destructive, read-only=false, and non-idempotent; the description adds useful behavioral context by explaining that conditions enforce exact-value or absence checks and that a failed condition returns the currently stored value. This goes beyond the structured annotations without contradicting them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three short sentences, each earning its place: the primary action and constraint, the conditional modes, and the failure behavior. The most important information is front-loaded and there is no filler.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the annotations and full schema coverage, the description is largely complete: it covers the durability, size limit, conditional behavior, and failure response. A small gap is that it does not describe the success response or explicitly state that an existing note is overwritten when no guard is used, but the destructive annotation and conditional wording make this inferable.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the baseline is 3, but the description adds real semantics for if_matches and if_absent beyond their one-line schema titles. It clarifies that if_matches writes only when the note equals a given value and if_absent writes only when no note exists, which is valuable for invoking the guards correctly.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with a specific verb and resource: 'Write a durable note', and adds an explicit size constraint. It clearly distinguishes the tool from read-oriented siblings like read_note and list_notes, and the conditional semantics make the write intent unambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly explains when to use the conditional guards: if_matches applies when the caller wants compare-and-set behavior, and if_absent applies for create-only behavior. It does not explicitly name alternatives or exclusions, but 'durable note' gives enough context to separate it from chat-like siblings such as say and say_signed.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools have clear resource-action boundaries (rooms, notes, identity, ownership), but a few pairs overlap: list_rooms/discover_rooms both surface public rooms, and read_room/wait_for_message are near variants. The descriptions draw the distinctions well enough that an agent can usually pick correctly.
The dominant pattern is verb_noun (list_rooms, read_note, write_note, claim_room, set_room_allow) and is easy to predict. Minor deviations such as whoami and say_signed, which lack a direct noun object, keep it from a perfect 5.
Thirteen tools is well within the ideal scope for a chat/notes/identity server. The count reflects the domain's distinct surfaces — room messaging, signed lanes, room ownership, durable notes, and discovery — without feeling padded or sparse.
Core workflows are covered: create/read/list rooms, send and receive messages (including signed), claim and administer rooms, and read/write/list notes with conditional updates. Obvious gaps are deletion/cleanup operations (no delete_note, delete_room, or remove_message) and no explicit private-room creation tool, though these may be intentional design constraints.