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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the not-found path returns the glossary's term list, which shapes how an agent should react to an empty result. It does not say whether matching is fuzzy or case-sensitive, which is a minor 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?

Three short sentences: the first defines the output, the second covers the error path, the third gives the trigger. Nothing is redundant and the most important information leads.

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 lookup with no output schema, fully covered: verb, example inputs, trigger condition, and fallback behavior are all present. No further An agent would need to call it correctly.

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 the baseline is 3, but the description adds value by listing six representative term types, signalling that the parameter must be a glossary-recognizable term rather than free text. That constrains agent input behavior in a way the bare schema string example does not.

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 ('gives a short plain-English definition of a data licensing term') and enumerates concrete example terms, so an agent knows exactly what output shape to expect. None of the sibling tools (readiness checks, rights checklists, handoff links, disclosure lists) overlap with glossary lookup, so no disambiguation is needed.

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?

'Use when someone asks what a data licensing term means' gives a clear trigger condition, and the fallback ('if the term isn't in the glossary, returns the list of available terms') tells the agent what happens on a miss. It stops short of naming an alternative tool, but no plausible sibling alternative exists here.

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