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

Annotations only cover readOnlyHint and openWorldHint, yet the description adds substantial behavioral context: an automatic LIMIT of 100 when missing, an 8-second execution cap, CC0 licensing, a $0.002 per-successful-call price via x402, and no charge on failed calls. These are exactly the traits an agent needs to plan and budget the call.

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?

Front-loads what the tool does, then packs the operational constraints (allowed query types, auto-LIMIT, timeout, license, price) into tightly worded sentences. Every clause carries distinct, actionable information with no filler.

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?

With an output schema present, return values need no elaboration, and the description correctly focuses on constraints and cost. For a single-parameter read tool it covers query-type restrictions, timeout, result capping, licensing, and billing—nothing an agent needs 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 description coverage is 100% and the single 'query' parameter is already documented as a SPARQL SELECT or ASK string up to 4,000 characters. The description reinforces the SELECT/ASK restriction and the auto-LIMIT behavior but adds no syntax or formatting detail beyond the schema, so the baseline 3 applies.

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: 'Runs a read-only SPARQL query on Wikidata.' This is clearly distinct from siblings like wiki and wiki_pageviews, which handle article content/pageview stats rather than structured SPARQL data. An agent can route here unambiguously.

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 clear operating context: only SELECT and ASK are allowed and updates are refused, which tells the agent what kinds of queries are valid. It does not, however, explicitly name when to prefer this over sibling tools (wiki, wiki_pageviews) or state exclusions, 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.