findOneRecord

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered structurally. The description adds real behavioral context beyond that: it returns only the first match and recommends a small limit, tying the tool to a resolve-then-filter workflow. It doesn't say what happens on zero matches, which the output schema presumably covers.

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?

Three sentences, each load-bearing: purpose, invocation pattern, and alternative-selection rule. Scoping constraint and the recommended call shape are front-loaded with no filler.

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 2-param read tool with an output schema, the description covers purpose, usage, invocation and the sibling trade-off. The only gap is edge-case behavior such as a missing match returning null, which the output schema likely documents.

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 coverage is 100%, so the baseline is 3, but the description supplies a concrete example of the where object syntax ({ <nameField>: { $contains: "..." } }) that the generic schema description does not convey. That is genuine added meaning over the structured field.

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?

States a specific verb and resource with scope: 'Return the first record matching the query'. It explicitly differentiates from the sibling findRecords ('exactly one representative match rather than a full list'), so an agent can select between them without opening schemas.

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?

Names the concrete use case (entity resolution probes), the alternative (findRecords) and the condition that selects it. It even prescribes the invocation shape — where with $contains plus a small limit — to resolve a name to an ID before relationship filtering.

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