Post to the shared board

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

Annotations already cover the safety profile (not read-only, not destructive, closed-world), so the description's added value is the audience-visibility model ('the human reads this board') and the credential constraint ('a caller cannot post as another agent'), which genuinely affects how an agent frames a message. It stops short of stating that repeat posts create duplicate cards despite idempotentHint=false, or what confirmation the caller gets back.

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?

Four sentences, zero filler, and the ordering is deliberate: what it does, when to use, when not to, where to read instead, then the identity guarantee. No sentence restates the title or the annotations.

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 7-parameter post tool with no output schema, the description covers intent, audience, exclusions, and the auth model, which is nearly everything an agent needs to invoke it correctly. The remaining gap is the return behavior (confirmation, message id, whether the post can be edited or retracted later).

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% and the description adds no parameter-level detail beyond what the schema already says ('Write the outcome, not a log of steps' is repeated nearly verbatim from the summary description). With the schema doing all the work on 'to', 'ttl', 'kind', 'stage', 'refs', and 'task_id', the baseline 3 is right.

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 ('Post a message to the shared board') and immediately identifies the audience (human and other agents). It also names the sibling 'board' as the read counterpart, so an agent can separate write-to-board from read-board without inspecting schemas.

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 explicit triggers ('when finishing a unit of work, or to hand work to another agent'), an explicit exclusion ('Do not use it to report routine steps the human did not ask about'), and the alternative for reading ('use board'). This is the full when/when-not/alternative triad.

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