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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and locality are covered. The description adds genuinely new behavioral context by disclosing the return shape (Markdown body plus review date and sources), which matters because there is no output schema. It does not describe behavior for a missing or malformed slug, which is the remaining gap.

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 no filler; the primary output description is front-loaded and the parameter instruction follows. Every clause carries information.

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 one-parameter read tool with annotations and no output schema, the description covers what is returned, in what format, and where the input comes from — enough to call it correctly. Only error/not-found behavior is unaddressed, which is minor at this complexity.

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 0% — the single 'slug' property is an undescribed string — so the description must compensate. It does add real meaning by identifying the slug's origin (list_guides), but it does not state the expected slug format or whether it is case-sensitive, leaving the parameter only partially specified.

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 names a specific resource and scope: 'the full text of one THRIVE guide as Markdown,' plus the supplementary payload (review date, sources). An agent can tell this is a single-item fetch rather than a listing, and the mention of list_guides further separates it from the sibling that enumerates guides. The verb is nominal rather than explicit ('returns the full text of'), which keeps it just 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?

'Pass the slug from list_guides' gives a concrete prerequisite and implicitly routes the agent through the listing tool first. There are no explicit exclusions or failure-mode guidance (e.g. what to do if the slug is unknown), so it falls short of full when/when-not coverage.

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