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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds the behavioral fact that this returns 'full text' from heterogeneous source namespaces, but says nothing about truncation when max_tokens is hit, rate limits, or other runtime behavior.

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?

A single front-loaded sentence with the verb and resource stated first, followed by a compact enumeration of id examples. Every element earns its place; there is no boilerplate or 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?

With an output schema present, return-value explanation is unnecessary, and annotations plus 100% schema coverage handle safety and parameters. The description supplies purpose and id format, leaving only minor gaps (truncation behavior for max_tokens, explicit routing versus 'search').

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. The description goes beyond the schema's generic '<source>:<key>' by giving four concrete id examples spanning different namespaces ('cso:', 'oireachtas:', 'legislation:', 'data-gov-ie:'), which materially helps the agent construct a valid id.

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?

Names a specific verb ('fetch') and resource ('the full text of a search result') and specifies the selector ('by its id'), so the agent knows this retrieves document content rather than finding documents. It implicitly distinguishes itself from the 'search' sibling by referencing 'a search result', but never names or contrasts that alternative explicitly.

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?

Usage is implied rather than stated: the phrase 'by its id' plus 'of a search result' signals the id must come from a prior search call. There is no explicit when-to-use, when-not-to-use, or named alternative among the siblings (search, ireland_describe, nearby).

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