mark_read

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

Annotations declare readOnlyHint=false and idempotentHint=true; the description adds real value beyond that by disclosing the externally visible side effect (read receipts / blue ticks are sent to the other party), which the annotations do not convey. It does not mention permission or account-switching requirements, but the annotation coverage makes the lower bar appropriate.

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?

A single efficient sentence with the action front-loaded and the consequence in the trailing clause; nothing is wasted. It is arguably too terse for the parameter documentation it omits, but as structure it is clean.

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?

An output schema exists, so return values need no explanation, and the annotations carry the safety profile. The remaining gap is parameter identification at 0% coverage, which the description does not fill for either 'chat' or 'account'.

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 0%, so the description must compensate, and it does not. 'Discussion' loosely maps to the required 'chat' parameter, but no format (JID/phone/ID) is given, and the optional 'account' parameter is never mentioned.

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 ('Marque une discussion comme lue') and even names the observable effect ('envoie les accusés de lecture (coches bleues)'). An agent can tell this apart from read-oriented siblings like get_chat or list_messages, though no sibling is named explicitly.

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 rather than stated: the reader infers one calls this after receiving messages the user has seen. There is no explicit when-to-use, when-not-to-use, or comparison against alternatives such as list_messages or get_chat.

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