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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds substantive behavioral context beyond them — the returned fields (prompt, source paper, reference band, word count, preview) and the hard cap of five results, which is a real constraint an agent must know. It does not mention ordering or how samples are selected, which keeps it below a 5.

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?

Three short sentences, front-loaded with what is listed and where from, then return contents, then the alternative tool. No filler, and the routing hint is placed last where it is most actionable.

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 no output schema, the description compensates by enumerating the returned fields, and it names the follow-up tool, so an agent has enough to call it and use the result. Minor gaps remain (no mention of how samples are ordered or filtered), but nothing essential is missing for a simple read-only list 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 coverage is 100% and the single 'limit' parameter already documents the range and default. The description's 'up to five model essays' reinforces the cap but adds no syntax or semantics the schema lacks, so the baseline 3 applies.

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 ('List public IELTS Writing Task 2 sample answers from Youshow IELTS') and immediately distinguishes itself from the sibling get_writing_sample by contrast (list/preview vs full essay). An agent can tell exactly what this returns without opening any schema.

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?

Explicitly routes the agent: 'Use get_writing_sample with a sampleId to read the full essay', which makes the list-then-fetch pattern obvious. It lacks an explicit 'when-not-to-use' statement (e.g., vs list_cue_cards), but the resource distinction is self-evident.

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