gmail_discover

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

Annotations declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is already covered. The description adds valuable behavioral context: it reveals hidden tools, requires being called first, and lists the operation names that become available, which is more than the annotations provide.

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 core purpose is front-loaded and clear, but the trailing operation list is long and ends with a confusing fragment ('+12 more; 58 generated ops: users'). It could be trimmed without losing essential meaning, though the operation names do provide useful context.

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 discovery tool with no output schema, the description is nearly complete: it explains the first-call requirement, the catalog reveal, and the tools it exposes. It does not explain the return format of the catalog or how the query parameter affects results, leaving minor gaps.

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 single parameter 'query' is fully described in the schema as 'Filter keyword'. The description does not add any meaning about how the query filters the catalog, so the schema carries the full semantic burden. This matches the baseline of 3 when schema coverage is 100%.

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 names the specific verb and resource ('Discover gmail') and states exactly what it does: lists the catalog and reveals hidden tools. It distinguishes itself from other service discovery tools by naming Gmail, and the instruction to call it first before invoking tools by name makes the purpose unambiguous.

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?

It gives clear sequencing guidance: 'call first, then call the tool by name.' This tells the agent when to use it relative to the hidden tools it reveals. However, it does not compare against sibling discovery tools like discover_all or explain when to use a service-specific discover instead.

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