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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered elsewhere. The description adds genuinely new behavioral context: no record payload is transferred and the operation is cheap, which matters for an agent choosing between counting and listing. It does not mention the shape or limits of the returned count, but the output schema presumably covers that.

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?

Two compact sentences, front-loaded with the core distinction (counting without transfer) and followed by the one operational hint. No filler or restatement of the title.

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 rich annotations, a 100%-covered two-parameter schema, and an existing output schema, the description supplies exactly the missing pieces: the count-vs-transfer distinction and how to obtain criteria field IDs. Nothing needed to select or invoke the tool correctly is absent.

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%, both parameters are documented, and the criteria shape is cross-referenced to glpi_search. The description goes beyond the schema by pointing to glpi_list_search_options as the way to discover valid criteria field IDs, which is actionable value the schema does not supply.

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 (count items) and immediately distinguishes itself from the list/search siblings by saying it counts 'without transferring them'. The parenthetical 'answers "how many" in one cheap call' removes any ambiguity about what the tool returns.

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?

The phrase 'without transferring them' implicitly routes the agent here when only a total is needed rather than glpi_search or glpi_list_tickets, and it explicitly names glpi_list_search_options for criteria discovery. It stops short of an explicit 'use instead of glpi_search when you don't need the records' statement or any exclusion conditions.

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