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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so 'Read-only and idempotent' largely repeats structured data. The description does clarify the lookup-by-identifier behavior and that the full definition is returned, which is modest added context but not rich behavioral disclosure.

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?

Three short sentences, front-loaded with purpose, then usage routing, then a return/safety note. Efficient, with only the redundant read-only/idempotent claim not earning much place against the annotations.

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?

A single-parameter, read-only lookup with an output schema, so return-format detail is not required. Purpose, routing and accepted identifiers are all covered; 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% and the single term_id parameter is well documented in-schema. The description adds one genuinely new fact — that a permalink is also accepted, alongside schema's slug/name and record ID — but otherwise does not extend parameter meaning.

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+resource ('Fetch a glossary term') and immediately names the accepted lookup keys. It also distinguishes itself from search_esg and search_content, so an agent can route correctly without opening the schema.

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?

Explicitly gives the when ('user asks about specific ESG terminology') and the alternative for a different intent ('to search for terms by topic use search_esg or search_content'). The selection condition is unambiguous.

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