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

Annotations already mark the tool as read-only and idempotent. The description adds valuable context beyond that: coverage specifics (412 codes, 270 with published rates, 38 national pay scales, 104 not eligible), the authoritative source, the update date, and a 'not advice' caveat. This gives the agent a good sense of data scope and limitations.

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 description is compact and front-loaded with the primary purpose, then adds only high-value details: coverage counts, source, update date, and a caveat. Every sentence earns its place, and there is no repetition of schema or annotation information.

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 read-only lookup tool with well-documented parameters and no required inputs, the description covers the key context an agent needs: what the tool returns information about, the acceptable lookup keys, and data coverage. It does not explicitly describe the output shape, but the absence of an output schema is partly mitigated by the clear domain scope.

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 baseline is 3. The description reinforces that queries use job titles and SOC codes, which mirrors the schema, but it adds no extra parameter-level detail such as formatting rules, precedence between query and soc, or how limit behaves beyond what the schema already supplies.

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 verb ('look up'), a precise resource (UK Skilled Worker visa going rate and minimum salary), and the lookup keys (job title or SOC 2020 code). It clearly identifies what the tool does and is readily distinguishable from the sibling tools, which cover licence checks and visa cost estimation.

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 clearly implies when to use this tool: whenever the goal is to find the going rate or minimum sponsored salary for a UK Skilled Worker role by job title or SOC code. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for an agent to select it appropriately.

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