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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered structurally. The description adds the ambiguity/candidates behavior, but says nothing about a no-match result, alternative identifiers, or lookup scope limits, so it adds only modest value beyond annotations and the output schema.

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 purpose is front-loaded in the first clause, but the final clause is literally redundant — "returns them all as candidates (ambiguous: true) with ambiguous: true" repeats the same flag twice. The second sentence also restates return fields the output schema already documents.

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?

With an output schema present, the description need not explain return values, and annotations cover the safety profile; what remains is adequate for a one-parameter read lookup. The only real gap is the not-found/zero-candidate case.

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% and there is only one parameter, so the baseline is 3. "By name or model number" restates the schema's own description of query without adding format, normalization, or matching-rule detail.

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 a specific verb and resource ("Look up one product in the Tethered Trust graph") and enumerates the payload (structured specs, accepts, fits), which is clearly distinguishable from multi-item siblings like find_parts. It never names a sibling tool or explicitly contrasts scope, so it stops short of a 5.

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?

Usage is implied: lookup a single product by name or model number, with a fallback stated when the text is ambiguous. There is no guidance on when to prefer this over identify_product, find_parts, or check_compatibility, and no exclusions.

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