get_circle

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, but the description adds real behavioral detail: the return shape (members plus per-member channel presence booleans) and a deliberate security constraint ("an identifier is NEVER returned — SEC-PM-006"). The auth prerequisite is also disclosed, which is exactly the kind of context annotations cannot carry.

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?

Front-loaded with the core action, followed by return contents and then access requirements, so the most important information comes first. The SEC-PM-006 reference and restart instructions add length but each earns its place; slightly dense for a single-parameter read.

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?

With no output schema, the description correctly shoulders the return-value burden by naming the members collection and the channel-presence booleans, plus the identifier omission. Auth setup and the sibling exclusion round it out, leaving only deeper field-level detail unstated.

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 description coverage is 100% and the single id parameter already carries its 24-hex-char pattern in the schema. The description only restates "by ID" without adding format, sourcing, or lookup guidance beyond what the schema provides, so the baseline 3 applies.

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?

States a specific verb+resource ("Get a Circle") and scopes it to a single record via "by ID", which cleanly separates it from list_circles, create_circle, update_circle and delete_circle without opening any schema. It also previews the payload (members, per-member channel presence booleans), so an agent knows what kind of retrieval this is.

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?

Provides clear operational context for when the tool will work ("needs a Proof account... Set PROOF_API_KEY and restart this server") and gives an explicit exclusion relative to a sibling: "start_login does NOT open this tool." It stops short of stating when to prefer this over list_circles, so it is context-rich but not fully alternative-routing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.