mcp_iati_list_sectors

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

With no annotations, the description carries the burden of behavioral disclosure. It does state the return shape as 'a table containing vocabulary, sector code, sector name and number of related activities,' which is useful. However, it does not disclose details such as ordering, behavior when data is empty, or whether the operation is strictly read-only, leaving some ambiguity.

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 well structured with clear sections for purpose, arguments, return value, and relevant IATI terms. It is slightly longer than necessary due to the vocabulary definitions, but those definitions support correct use and the key information is front-loaded.

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 one-parameter tool with an output schema, the description covers the core needs: what the tool lists, when to use it, what the result table contains, and the parameter meaning. Minor gaps such as handling of missing data or ordering do not significantly impair an agent's ability to invoke it correctly.

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 input schema has no parameter descriptions, but the description explains 'limit' as the 'Maximum number of sector values to return' with a default of 100. This adds meaningful semantics beyond the bare integer type and default value in the schema.

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: 'List the sectors present in the loaded IATI data.' It also clarifies that the tool returns sector codes and vocabularies, which distinguishes it from sibling list tools like mcp_iati_list_activity_statuses or mcp_iati_list_recipient_countries.

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 explicitly says to use the tool 'to discover the available sector codes and vocabularies before performing sector-based analysis.' This gives clear context for when to call it, though it does not name alternatives or explicitly state when not to use it.

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