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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the description is free to add real value — and it does, disclosing the default result count (five), the exact returned fields (used_for, animated, slots, hint, fits_chars), and the default animation behavior. That last sentence ('one of them is animated, unless you set animated') is worded ambiguously enough that an agent may misread the default filter.

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?

Front-loaded with the key routing phrase and then a compact workflow, and nearly every clause carries information (return shape, slot semantics, next-tool call). The final sentence is a run-on whose meaning is harder to parse than it needs to be.

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 fully covers the return shape, including nested slot fields, and ends with the concrete next action. Nothing an agent needs to select and invoke this correctly is missing.

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 67%, with `limit` having no schema description at all; the description compensates by stating the default is five templates. 'Unless you set animated' and 'in Spanish or English' add behavioral meaning to the other two params beyond their schema text. Only the maximum of 8 for limit remains schema-only, which is fine.

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: give a joke/situation, get ranked templates with used_for, animated flag, and per-slot hint/fits_chars. It is clearly differentiated from create_meme by positioning itself as 'the best first step' and handing off to create_meme, but it never contrasts itself with search_templates, popular_templates, or get_template, so an agent must infer why this beats those.

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?

Strong workflow context: use it first, then pick by used_for/hints, write a caption per slot under fits_chars, and call create_meme with the slot numbers. It also gives a selection rule for the animated parameter. It lacks any explicit when-not-to-use or naming of the sibling search tools as alternatives.

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