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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and closed-world, so the safety profile is covered. The description adds a genuinely useful behavioral detail beyond the annotations: the response is unpaginated and returns all entries at once, which matters for payload sizing. It stops short of describing entry count or any filtering limits, so not a 5.

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 sentences, each earning its place: what is returned, in what volume, and when to choose this vs. the sibling. The routing constraint is placed last but the purpose is front-loaded.

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?

An output schema exists, so return-field details need not be repeated, and the description still notes the unpaginated-all-entries behavior, which is the one return trait an agent must anticipate. For a zero-parameter read tool, nothing needed 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline is a 4. The description instead spends its words on output shape rather than inventing nonexistent parameters, which 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 (Lists) plus resource (published glossary entries) and enumerates the terminology domains covered, along with what each entry contains (term, definition, metadata). This clearly distinguishes it from article-oriented siblings like search_articles and list_articles.

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 names the triggering case ('term definition questions — "what is X?"') and routes the agent to the correct alternative when a method explanation is wanted ('prefer search_articles'). Both when-to-use and when-to-use-something-else are stated.

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