search_customers

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

Annotations are absent, so the description must fully disclose behavior. It claims read-only and idempotent, but the description includes contradictory statements: it says 'No authentication required' but later mentions API key for Pro/Enterprise tiers. Also, it says 'read-only and produces no side effects' which is consistent, but the description's generic 'When to use' text about 'analysis or classification' is misleading. The rate limits and privacy details add value, but the inconsistency lowers the score.

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?

The description is overly verbose with redundant sections. It repeats 'read-only', 'no side effects', and 'idempotent' multiple times (in the opening, in Behavioral Transparency, and in other sections). The 'When to use' section is generic and irrelevant, adding noise. The front-loading is good with the clear first line, but the length and repetition undermine conciseness.

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?

Given the tool has no output schema, the description must explain return format; it mentions error objects but not successful response structure. The description covers safety, rate limits, and idempotency, but the instability with auth requirements and the generic usage guidelines leave gaps. The tool's purpose of searching customers is simple, but the description's extraneous content and contradictions limit completeness.

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 schema has 0% description coverage for parameters, and the description introduces a third parameter 'api_key' not shown in the schema's properties (actually it is in the schema but not documented in the description). The description explains 'query' and 'limit' in Args, but does not explain 'api_key', and the schema itself lacks descriptions. The description provides some details for query and limit, but fails to cover all parameters, leaving the agent to guess about api_key.

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 clearly states the tool searches Stripe customers by email or name, which is a specific verb and resource. However, it does not explicitly differentiate from sibling tools like list_invoices, but the purpose is clear enough for an agent to understand its role.

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?

The description includes a 'When to use' section that is generic and mentions 'structured analysis or classification', which seems unrelated to searching customers. There is no explicit mention of alternatives among siblings, and the 'When NOT to use' is vague and not directly about customer search.

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