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

Annotations already declare this as a safe, idempotent, read-only, closed-world search, so the safety profile is covered. The description adds real behavioral context beyond that: the result shape (slug, category, page link) and the notable quirk that only the top 3 results include input keys, defaults and allowed values — information an agent needs before chaining into run_calculator.

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-loaded with verb, resource and corpus size, then return shape, then usage — a logical order with no filler sentences. It is somewhat dense with parenthetical example lists, which slightly burdens readability but every clause carries information.

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?

There is no output schema, so the description correctly compensates by describing what results contain and how the top-3 enrichment enables chaining. Combined with annotations covering the safety profile, an agent has everything needed to call it correctly and act on the result.

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 both 'query' and 'limit' are already documented in the schema, establishing a baseline of 3. The keyword examples ('mortgage', 'bmi', 'kg to lbs') are helpful illustrations of query format but add no constraint or syntax detail beyond what the schema states, and 'limit' is not discussed at all.

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?

The description states a specific verb and resource ('Searches Calcupedia's 2,400+ calculators and unit converters by keyword') and scopes the corpus precisely. It is immediately distinguishable from siblings like run_calculator and calculate, which execute rather than locate calculators.

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?

It gives explicit triggers ('when the user wants a number worked out ... a loan, interest, savings, tax, salary, BMI, calories, date or age, percentage or unit conversion') and routes to the next step: 'then pass the slug to run_calculator.' The alternative (run_calculator) is named with the condition that selects it.

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