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

The readOnlyHint=true annotation already tells the agent this is a safe read, so the description need not re-declare safety. It adds the backing endpoint (GET /v1/customers/), but says nothing about pagination behavior, result limits, or scoping caveats beyond what the schema carries.

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?

Two short sentences, front-loaded with the core action and filtering capability. The trailing endpoint reference is minor and slightly redundant but not wasteful; nothing else bloats the definition.

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?

For a read-only list tool with a fully documented schema and no output schema, the definition is adequate but thin. It omits any mention of the returned collection shape or that organization_id may be needed for multi-org tokens, leaving those to the schema.

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%, so all five parameters (page, limit, email, query, organization_id) are fully documented in the schema. The description restates only email and query, adding no format or syntax detail beyond what the schema already provides, 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 ('List') and resource ('customers') and notes optional filtering by email or text query, which clearly separates it from polar_get_customer. It does not explicitly name siblings, but the list-vs-get distinction is inferable from the verb.

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 phrase 'optionally by email or a text query' hints at when the filters are useful, implying a browse/search use case. However, it never states when to choose this over polar_get_customer or the customer_state tools, nor any exclusions, leaving guidance implied rather than explicit.

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