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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds valuable context beyond annotations: 'No API key needed' and the distinction between tool surfaces (tools/list vs tools/call). It does not contradict any annotation and enhances understanding of the tool's behavior.

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 tight sentences plus a clarifying note. The key urgency signal ('No API key needed — call this now') is front-loaded, and every sentence earns its place without fluff. It is appropriately sized for the tool's simplicity.

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 guide tool with an output schema present, the description covers input semantics, usage scenarios, and the tool's relationship to the broader system. It does not need to explain return values since the output schema exists. No critical context is missing for an agent to select and call it correctly.

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 documents the topic parameter well. The description adds value by listing the exact accepted keywords and explaining the effect of omission. This goes beyond a bare schema description, though it partially repeats the schema's list. It still enriches semantics with the catalog/sequence distinction.

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 this is a 'Navigator for the full A2AWire tool surface' and describes its function: returning a catalog or recommended call sequences. The verb 'call' and resource 'A2AWire tool surface' are specific, and it distinguishes from siblings by being a guide rather than a specific operation like check_earnings or data_preview.

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 explicitly tells when to call it: with no topic for the catalog, or with a specific topic for a sequence. It also clarifies the relationship to other tools, noting that listed tools are callable via tools/call and that tools/list shows only essentials. This provides clear usage guidance without ambiguity.

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