User comments on a phone

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered; the description adds genuinely new context — that content is unverified user-generated text and that author names are deliberately omitted. With no output schema, the note about Persian-calendar dates and the `reply_to` threading field is also useful disclosure about what comes back.

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?

Three front-loaded sentences with no padding: purpose first, usage second, content caveats third. The closing `reply_to` sentence is somewhat orphaned since it describes a response field rather than a parameter, which slightly muddies an otherwise tight structure.

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?

For a three-parameter read tool with no output schema, the description covers what matters: the device scope, the fields returned, the unverified nature of the content, and the absence of author names. Pagination/sort behavior and the limit cap are left to the schema, which documents them adequately, so nothing essential 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 description coverage is 100%, and all three parameters (id, sort, limit) are fully documented in the schema including the enum meaning for 'helpful' and the id provenance. The description's only parameter-adjacent sentence explains `reply_to`, which is actually a return field rather than an input, so it adds no input-side semantics beyond the schema.

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 ('Read what Mobile.ir users wrote about a phone, tablet or watch') and enumerates the returned content, so the agent knows exactly what this tool produces. It also positions itself against the sibling mi_phone by framing itself as the qualitative counterpart to that tool's rating.

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?

Explicitly says to use it 'for real-world opinions (battery, camera, durability) next to mi_phone's rating', which gives a clear situational trigger and names the complementary sibling. It stops short of stating exclusions (e.g., when to prefer mi_articles or mi_used_ad for opinion content), so it is clear context rather than a full when/when-not matrix.

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