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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description still adds genuine value beyond them: it discloses what is returned (sources and revision) and the not-found behavior for ambiguous input, which the annotations cannot express.

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 sentences, front-loaded with the primary action and return contents, followed by a short failure-mode note and disclaimer. Every sentence carries distinct information and there is no 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?

With one required, fully documented parameter, no output schema and rich annotations, the description covers the essentials: what comes back, what happens on a miss, and a scope caveat. A brief note on identifier matching or case sensitivity would close the last gap.

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 single parameter's description already lists 'Exact glossary term, alias, ID or slug.' The description restates the same set of accepted identifier forms, so it adds corroboration rather than new meaning such as matching rules or case sensitivity. Baseline 3 is appropriate.

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 ('Get a complete approved glossary entry') and enumerates the identifier forms it accepts (exact term, alias, ID, slug). This clearly separates it from lookup siblings like search, search_providers, and get_article, which are list/query tools rather than exact-key retrieval.

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 word 'exact' and the note that 'an ambiguous or unavailable term returns not found' implicitly tell the agent this is not a fuzzy search and that a miss is a valid outcome rather than an error to retry. It stops short of explicitly routing the agent to a search sibling when the exact identifier is unknown, so it is strong but not complete.

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