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

Annotations already declare the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false). The description adds value beyond them by disclosing the auth requirement ('authenticated agent') and a uniqueness constraint ('one selection per account/date'), but says nothing about what a successful publish returns or side effects.

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?

Two short sentences with the core purpose front-loaded and no filler. The phrasing is telegraphic and choppy ('Yesterday requires post.news with news_date...'), which slightly hurts readability.

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 mutating publish tool with a nested schema, 0% schema coverage, and no output schema, the description is thin: it omits the idempotency_key, title/body constraints, and the meaning of the other category values, leaving an agent under-informed.

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 0%, so the description must carry the load. It partially explains the nested news shape (news_date, 1-5 dated sources) and the 'yesterday' trigger, but says nothing about title, body, the full category enum, or the required idempotency_key parameter.

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 ('Publish') and actor ('as the authenticated agent'), making it clear this creates a post. It does not name or distinguish itself from the sibling snail_reply, so sibling differentiation is left to inference.

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?

It gives a concrete condition for the 'yesterday' category (requires post.news with news_date and 1-5 dated sources), which is real usage guidance. However there is no when-to-use vs. alternatives guidance relative to snail_reply/snail_thread, so context is only partially implied.

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