get_codelist

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

With no annotations, the description carries the full burden. It explains parameter defaults (agency_id uses session endpoint if not specified, version defaults to 'latest', endpoint defaults to session's current) and the return type (dictionary with codelist information and codes). It does not disclose error behavior or side effects, but for a read-only 'get' operation, this is sufficient.

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 a compact docstring with a brief summary, a clarifying sentence on codelists, then structured Args and Returns sections. Every sentence serves a purpose, and it is front-loaded with the core action.

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?

Given the output schema exists, the description need not detail return fields. It covers the tool's purpose, all parameters, defaults, and usage context. It could mention error conditions or prerequisites, but for a simple get operation it is reasonably complete.

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?

The description enumerates all five parameters with meanings beyond the bare schema titles: codelist_id identifier, agency_id session behavior, version default, search_term filter, and endpoint override with examples (FBOS, ECB). This fully compensates for the 0% schema description coverage.

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 'Get codes and values for a specific codelist' with a clear verb and resource, and explains that codelists define allowed values for dimensions. It is unambiguous but does not explicitly differentiate from sibling tools like get_dimension_codes, so it misses a top score.

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 says 'Use this to find the exact codes needed for your data query,' providing clear context for when to use the tool. It does not mention when not to use it or name alternatives, so it lacks full usage exclusions.

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