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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds return-shape context not present elsewhere ('returns the definition with a link to the full entry'), which is valuable since there is no output schema. It omits miss behavior (what happens when a term isn't found).

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 with the verb and scope front-loaded, followed by the usage condition. Efficient and free of filler, though the example list lengthens the first sentence slightly.

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-only lookup with no output schema, the description covers what it does, when to use it, and roughly what comes back. Only the not-found/ambiguity behavior is missing, which is a minor gap 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 description coverage is 100% for the single 'term' parameter, so the schema already documents it. The example terms ('ICR', 'Section 24', 'gross yield', 'void period') add mild signal about accepted inputs but no format or matching rules 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 ('looks up a UK property investment or landlord tax term in the RealYield glossary') plus concrete example terms. This clearly separates it from the sibling calculators and search tools, which do not define terminology.

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 usage context: 'Use it when a reader asks what a term in an article means.' It does not name an alternative for the adjacent case (e.g. search_realyield for non-glossary lookups), so it stops short of full when/when-not guidance.

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