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

The description adds meaningful behavioral detail beyond the readOnlyHint annotation: it explains that settings contains stored values while effectiveSettings includes runtime defaults, and warns that effectiveSettings must not be copied into unrelated updates. It also tells the agent to use the returned revision as expectedRevision, which is critical for correct update behavior. This goes well beyond the annotations.

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 sentences with no filler. The primary purpose is front-loaded, followed by critical field semantics and permission. Every sentence adds useful information for correctly using the tool.

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 read tool with one parameter and an output schema, the description covers what matters: the read-before-edit workflow, revision handling, effectiveSettings caveats, and required permission. The output schema handles return value details, and annotations cover safety, so nothing essential 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 schema has 0% description coverage for agentId, and the description does not explicitly explain what agentId is or where to obtain it. The name 'agentId' is self-explanatory, but in a 0% coverage situation the description should at least mention that agentId identifies the agent to read, or point to list_whatsapp_agents. It does not compensate for the schema gap.

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 a specific action and resource: 'Read one discovered WhatsApp agent before editing.' It distinguishes this from sibling tools like list_whatsapp_agents and update_whatsapp_agent by focusing on reading a single agent in preparation for editing. No ambiguity remains about what the tool does.

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 provides clear usage context: it should be used before editing, and the returned revision should be passed as expectedRevision. It also mentions the required permission. It does not explicitly name alternatives or exclusions, but the 'before editing' cue strongly implies the intended workflow, so this is clear context without explicit exclusions.

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