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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real behavior beyond them: the exact-match-first then partial-match lookup strategy, the shape of the result, and a 200/day per IP free quota. Missing only what happens when no match is found.

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 first sentence is well front-loaded and does the core work. The appended pricing JSON object is bulky and partly redundant with the fixmyplant_pricing sibling, though the free-quota line has some value for the agent.

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 carries the burden of describing return values, and it does so at a high level (toxic-to audience and symptoms). For a one-parameter read tool this is nearly complete, with only the no-match result undefined.

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 baseline is 3, but the description earns a bump by explaining how the single 'plant' string is interpreted: exact match is tried first, then a partial match. That matching semantics is not in the schema, which only says 'plant'.

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 (look up a plant in the toxicity list by name) plus what it returns (who it is toxic to, listed symptoms). This clearly separates it from fixmyplant_about, fixmyplant_care_guide, and fixmyplant_pricing.

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 implied by the purpose: use it when you need toxicity information for a named plant. It gives no explicit when-not-to-use guidance and does not name fixmyplant_care_guide as the alternative for general care questions, leaving the agent to infer the boundary.

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