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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds useful context that customers map to the `accounts` model and that this is a GET /accounts request, but it omits rate limits, pagination defaults, and permission requirements.

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 sentences, front-loaded with the action and immediately followed by the model/endpoint mapping. The capabilities list ('filtering, sorting, search, and expansion') lightly repeats what the schema already shows, but overall it is efficient and has no real waste.

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 rich schema (100% coverage), readOnlyHint annotation, and no output schema, the description is largely complete for a list tool. It identifies the endpoint and model, though it could say more about return shape or default pagination behavior.

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 the schema already documents all six parameters with examples. The description only broadly references filtering, sorting, search, and expansion without adding syntax or semantics beyond what the schema provides, which matches 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 ('List customers') and clarifies the underlying Swell model and endpoint ('customers are the `accounts` model — this queries GET /accounts'). It does not explicitly differentiate from close siblings like swell_get_customer or swell_query, so it falls short of a 5.

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?

No guidance on when to use this tool versus alternatives such as swell_get_customer for a single record or swell_query for generic querying. The mention of 'filtering, sorting, search, and expansion' implies bulk retrieval but does not state the conditions or exclusions.

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