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

Annotations already cover readOnly, idempotent, non-destructive behavior, lowering the disclosure burden. The description adds useful context about project scoping and conditional nested location/tags inclusion, which is not present in the annotations. No contradiction exists.

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 substantive sentence is tightly worded and front-loaded, but the description begins by repeating the tool title 'Get Customer' before adding real content. Overall it is concise and easy to parse.

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 simple one-parameter read operation with an output schema and safety annotations, the description provides everything needed: resource, cardinality, project scope, and optional nested data. No critical information for correct invocation 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?

The input schema fully documents the 'id' parameter as a unique numeric identifier with 100% coverage, so the baseline of 3 applies. The description adds no additional meaning about the parameter beyond what the schema already provides.

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 'Retrieve one customer belonging to the authenticated project with nested location and tags where present,' providing a specific verb, resource, cardinality, and scope. This clearly distinguishes it from listCustomers (many customers) and getLocation (location resource).

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 clearly implies use when a single customer is needed by ID within the authenticated project, especially when nested location and tags are desired. However, it does not explicitly name alternatives or state when not to use this tool.

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