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

With only readOnlyHint/openWorldHint annotations, the description carries the return-value burden and does so well: it enumerates the five answer states (Works, Works with a limit, Needs extra hardware, Does not work, Not confirmed), the evidence words, and clarifies the easily-misread 'Not confirmed means unknown, never incompatible'. That is substantial behavioral context beyond the annotations.

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?

Four sentences, front-loaded with the resource and then the result semantics and parameter hint; little waste. Slightly dense enumeration of statuses but each clause carries information.

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?

No output schema exists, and the description compensates by describing the answer values, evidence categories and source link, which is what an agent needs to interpret results. Minor gap: it does not mention pagination or whether all compatibility items are returned when query is omitted.

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 the schema already documents both parameters and its query example. The description adds only a marginal nuance about narrowing to a single thing ('e.g. iphone or android'), which overlaps the schema's own example. Baseline 3 is appropriate.

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 (get) and resource (compatibility) with precise scope: 'what a product works with, from its Guide's Works with tab'. The scope distinguishes it from siblings like get_product_facts, get_in_the_box and get_detailed_facts, which cover different aspects of a product.

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 content (answering compatibility questions) and the optional query parameter ('narrows to one thing'), but there is no explicit when-to-use/when-not or named alternative such as get_product_facts. An agent can infer the context but must choose between siblings on its own.

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