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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior, so the safety profile is fully covered. The description adds only that include 'loads parent chains', which is mild extra context; it says nothing about missing-id errors or auth requirements.

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?

Two short sentences, zero filler, with the primary action (fetch by id) front-loaded before the optional parameter. Every clause earns its place.

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?

Adequate for a simple get-by-id tool, but with no output schema the description does not describe the returned citation shape, and it omits error behavior when the id does not exist. These gaps are minor but real for a fetch tool.

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%, including the full whitelist of include values, so the schema carries the parameter documentation. The description only restates include's purpose ('load parent chains'), adding a little meaning but no syntax or format detail.

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?

States a specific verb and resource ('Fetch a single citation by its numeric id'), which cleanly separates it from the sibling list-citations-tool by cardinality. It does not name that sibling explicitly, so an agent must infer the single-vs-list distinction.

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 only implied: 'by its numeric id' signals a lookup when you already know the id, and the include clause hints at when to request related data. No alternative tool is named and no condition for choosing this over list-citations-tool is stated.

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