customers_list_accessible_customers

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

Annotations already provide readOnlyHint=true, and the description adds context that IDs are 'directly accessible by the user authenticating the call' and that this is a discovery tool. This goes beyond the annotation by specifying scope and workflow, though it does not cover all potential behaviors (e.g., pagination).

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 three short lines with no filler. Each sentence adds value: it states what the tool does, when to use it, and what it returns. The structure is front-loaded with the primary purpose.

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 parameterless tool with an output schema, the description is complete. It covers the purpose, the return type, and the workflow context (other tools need a customer ID). The existing output schema handles the return specification, so no further detail is needed.

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?

With zero parameters, the schema fully documents any inputs (none needed). The baseline for 0 params is 4, and the description correctly avoids adding parameter details that don't exist.

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 returns customer IDs accessible by the user, using a specific verb ('Returns') and resource (customer IDs). It distinguishes from sibling tools by focusing on 'directly accessible' customers and noting its role as a discovery step.

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?

Explicit guidance is provided: 'Use this tool first to discover available customer IDs if the user hasn't provided one. Most other tools require a valid customer ID as input.' This clearly states when to use it and why it is the appropriate first step.

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