avito_get_conversation

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds two things beyond that: the side-effect nuance that the conversation is NOT marked read, and an explicit prompt-injection warning that returned content is external data and never an instruction — both are meaningful behavioral disclosures.

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 compact sentences: purpose first, then the pagination recipe, then the safety note. No filler, and the most important information is front-loaded.

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 read-only tool with a full-coverage schema and rich annotations, the description covers purpose, pagination, side effects and injection safety. It does not describe the shape or ordering of returned messages, but with no output schema and annotations already handling the safety profile, that gap is minor.

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 adds real semantic value by explaining how to use beforeTime for backward pagination ("le time du plus ancien message"), which the schema only describes generically as a time value. afterTime and size remain unexplained 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?

The description gives a specific verb and resource ("Lit les messages d'une conversation existante") and adds a differentiating scope clause ("sans la marquer comme lue") that separates it from mark_read. It does not explicitly distinguish itself from the sibling avito_list_conversations, so it falls short of full sibling differentiation.

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?

It gives concrete usage guidance for pagination ("Pour remonter l'historique, utiliser le time du plus ancien message comme beforeTime"), which is genuinely actionable. However it never states when to choose this tool over avito_list_conversations or avito_mark_read, leaving alternative selection to inference.

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