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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so the safety profile is covered. The description adds real operational value on top by disclosing that the source is free, requires no API key, and is CC0-licensed, which matters for credential and licensing decisions. It omits rate limits and pagination/truncation behavior beyond the schema's max of 50.

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 tight sentences, front-loaded with the action and resource, then the return contract, then the use case. Zero filler, and every sentence earns its place.

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-value structure need not be explained, yet the description still summarizes the key returned fields. With full schema coverage, an unambiguous purpose, license/auth context, and a stated use case, the agent has everything needed to select and call this three-parameter tool 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 description coverage is 100%: query, limit (default 10, max 50) and language (default en) are all documented in the schema with defaults and bounds. The description adds no parameter-level detail such as language-code format or what a broad/narrow query text yields, so this is the baseline 3.

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 ('Search Wikidata entities by label') and names the return shape (Q-IDs with labels, descriptions, entity URLs). It is immediately distinguishable from siblings like wikipedia_summary or wikimedia_pageviews.

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 to resolve people, organizations, places and concepts to stable identifiers' gives a clear task context and tells the agent what class of problem this solves. It does not, however, name an alternative tool or state when a different sibling (e.g., wikipedia_summary) should be preferred, so it falls short of a 5.

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