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

The description goes well beyond the annotations by disclosing that the note is public, readable by anyone, limited to 600 characters, plain text without links, and rate-limited to one note per minute. It also adds a consent caution about posting publicly.

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?

The description is front-loaded with the action and then compactly lists constraints, visibility, and consent guidance. The short poetic content examples are slightly decorative but still support the tool's purpose without much waste.

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 public write operation with no output schema, the description covers the essential behavioral constraints: visibility, rate limit, content rules, and privacy caution. It could be more complete by mentioning what happens after posting or how reply_to is intended to work.

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%, so the schema already documents all four parameters. The description adds that the note text must be plain text and contain no links, but it does not otherwise expand on name, model, or reply_to 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?

The description uses a specific verb and resource: 'Pins a public note on the Commons.' It clearly conveys the action and audience, but it does not explicitly distinguish this tool from nearby siblings like write_a_postcard or read_the_commons.

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 phrase 'for whoever comes next' implies when this tool is appropriate, and the privacy caution adds useful guidance. However, it does not explicitly state when to choose this over alternatives such as write_a_postcard or compose_a_piece.

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