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

With no annotations, the description carries the full behavioral burden, yet it discloses nothing beyond a vague notion of completeness: no behavior on missing/invalid id, no permission or scope requirements, no error semantics, and no indication of what 'in full' actually includes.

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?

It is short, but this is under-specification rather than conciseness: a four-word fragment with no verb and no front-loaded actionable information. Brevity here does not earn a good score because nothing useful was compressed.

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 retrieval tool with no annotations, no output schema, and an undocumented parameter, the description is completely inadequate; an agent cannot know what it gets back, what the id must look like, or how it relates to the other source-related tools.

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 single required parameter 'id' has 0% schema description coverage and the description adds no meaning whatsoever, not even that the id identifies a specific source or where it comes from. Compensation for the coverage gap is entirely absent.

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 fragment 'One catalogue entry in full' has no verb and does not use the tool's own resource name ('source'), instead calling it a 'catalogue entry', which leaves an agent inferring that get_source returns a single source record. It only weakly distinguishes itself from search_sources or the list_* siblings via the singular/full-record implication.

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?

There is no guidance on when to call this versus search_sources or the list_* siblings, no prerequisite (e.g. needing an id from a prior search), and no exclusion conditions. Nothing in the description tells the agent how to choose this tool.

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