msg_read

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

With no annotations, the description carries the full behavioral burden and does disclose the critical side effect: unread messages are 'marked read' as a result of the call. It omits permissions, concurrency, or rate-limit details, but the mutation disclosure is the most important trait and it is present.

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 tight sentences with zero filler, leading with purpose and side effect before usage timing. Every clause earns its place.

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?

For a small read tool with no output schema and no annotations, the description covers purpose, default behavior, the state-changing side effect, and call timing. Return format is unspecified but not essential for correct invocation.

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 baseline would be 3, but the description adds real meaning: it explains the default read-unread behavior and clarifies that all_history=true 'lists the whole exchange,' which sharpens that parameter beyond the schema's wording. Only the topic parameter is left without added semantics.

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 and resource: 'Read messages addressed to you (and broadcasts).' This clearly distinguishes it from write-oriented siblings like msg_send, though it never names msg_board or explains how it differs from that read-like sibling, keeping it short of a 5.

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?

Gives concrete timing guidance ('Call before starting work and after finishing a chunk') plus the key default-vs-history mode. It does not name an alternative sibling or an exclusion condition, so it is clear context without full routing.

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