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

Annotations only say it is a non-read-only, non-destructive write; the description adds the substantive behavior: refusal when 'version' does not match the current edition, append-only permanence ('never changed or removed'), and that the record captures who/when/which edition. That is exactly the extra context annotations cannot convey.

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 action and the identity constraint, then the failure mode, then eligibility, then semantics. Slightly dense with the quoted phrasing, but every clause carries operational meaning rather than filler.

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 two-parameter write tool with no output schema, it covers the action, the identity requirement, eligibility, the failure condition, and the immutable recording model. Nothing an agent needs to call it correctly is missing.

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 is 3; the description goes further by constraining 'version' to the 'edition' value returned by get_wiki_page_reading and explaining the refusal consequence of a mismatch. 'id' gets no added semantics beyond the schema.

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 ('Mark a wiki page as READ'), plus a distinguishing scope qualifier ('IN YOUR OWN NAME'). It is unmistakably different from get_wiki_page_reading or set_wiki_page_readers, which an agent could otherwise confuse it with.

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 when-to-use ('make it when your person told you they have read the page'), explicit when-not ('not because you fetched its text'), a prerequisite ('Only for somebody the page is required reading for'), and routes to the sibling that supplies the required value.

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