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

readOnlyHint=true is already declared, so the agent knows this is a safe read. The description adds genuinely useful behavioral context — the poem is randomized and curated to be context-free — but says nothing about repeatability across calls, how 'good' is determined, or what a narrowed-but-empty result yields. With annotations carrying the safety profile, this is adequate but not rich.

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 sentences, both front-loaded: the first establishes what is returned and why it exists, the second covers filtering. No filler or restatement of the title.

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 format need not be described, and annotations cover the read-only profile. The description still supplies the two things structured data cannot: the randomization/curation behavior and the intended hand-off use case, which is enough for correct invocation.

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 four enum-ish filter fields are already documented in the schema. The description adds the framing that these four dimensions 'narrow' the random selection, which the schema does not state, giving the agent filter semantics beyond the raw property list.

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 uses a concrete verb and resource ('one good poem at random') and pins down the selection criteria ('stands alone without context'), which distinguishes it from search_poems/list_poems by intent rather than by name. It is clear what the tool returns, though no sibling is explicitly called out.

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?

It gives a clear use context ('for handing to someone rather than looking for one') that separates it from browsing/search tools, and states that results can be narrowed by four facets. It stops short of naming alternatives like get_poem or search_poems or stating exclusions, so it is context without routing.

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