fuzzy_match

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world. The description adds genuinely new behavioral facts: that the result is deterministic and that matches are returned in descending score order. It stops short of stating result payload shape or big-haystack performance characteristics.

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 tight sentences, with the core operation front-loaded before the use-case list. No filler or repetition. Slightly over-compressed on the return-value side, but every sentence earns its place.

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 no output schema, the description carries the burden of describing the return value, and it only says 'best matches in descending order' without stating whether results are bare strings or string/score pairs. With four parameters and no output schema, more precision about the response was warranted.

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 needle, haystack, topN and threshold are already documented in the schema; baseline is 3. The description clarifies that scoring is per-candidate against the query, but adds no format or edge-case detail (e.g. empty haystack, threshold semantics) beyond what the schema provides.

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 a specific operation (score candidate strings against a query), the exact algorithm (Sorensen-Dice over character bigrams), and the output ordering. It is unambiguous about what the tool does. However, it makes no attempt to distinguish itself from the sibling tool 'similarity', which likely overlaps, so it falls 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?

It lists concrete use cases (deduplication, record linkage, typo-tolerant lookup, disambiguation), which implies when to use it. But it names no alternative and no exclusions, and conspicuously ignores the close sibling 'similarity', leaving the agent to guess which is appropriate.

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