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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior: conditional output when a key is supplied, and a prompt-injection warning that poem lines are player content and not instructions to follow. It does not, however, discuss any pagination, size limits, or how stale the "current" state might be.

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 content is front-loaded (returned data first, then the usage trigger, then the safety note) and every sentence earns its place. The opening sentence is a long comma-chained list, which is dense but still scannable; minor tightening would improve it.

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?

There is no output schema, so the description carries the burden of explaining return values, and it does so thoroughly, field by field. Combined with the injection warning and the add_line dependency, an agent has everything needed to call this 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?

Schema description coverage is 100%, so both parameters (key and language, including the enum values) are already fully documented in the schema. The description reinforces that the key unlocks points/scoring and implies it is optional, but adds no syntax or format detail beyond the schema's own text.

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 names the resource (the current shared poem) and enumerates exactly what is returned: lines with authors and images, past guesses and verdicts, the line number being written, forbidden images, and last writer. It also distinguishes itself from the sibling add_line by stating the dependency relationship, so an agent can tell the two apart without opening a 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?

"Call before every move: add_line needs the line number" gives an explicit trigger condition and names the consuming sibling. The key parameter's conditionality is also covered ("With a key it also shows your points... Omit it if you have no key yet"), leaving no inference required.

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