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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read operation. The description adds no behavioral details beyond listing the resource, such as rate limits, authorization requirements, or response format. It does not contradict annotations, but it also doesn't provide extra context, so a 3 is 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?

The description contains two sentences, but the second sentence is a near-verbatim repetition of the first part: 'Guidance: List CMS photo gallery items, optionally filtered by one photo gallery section.' This redundancy wastes space and could confuse the agent. A concise single sentence would suffice.

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 list tool with no output schema, the description covers the action and main filters but does not explain the structure of returned photo items or how filters combine (e.g., AND vs OR). However, given that the sibling cms_get_photo likely describes a single photo object, and the parameters are well-documented, it is reasonably complete, though not exhaustive.

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%, meaning every parameter has a description in the schema. The tool description lists the filter categories but adds no additional meaning beyond what the schema already provides. For instance, the schema already explains that 'section' is returned by cms_list_cms_sections. The description is redundant here, so a 3 is given.

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 clearly states the verb 'List' and the resource 'CMS photo gallery items', and enumerates the available filters (section, status, search, pagination, id, sorting). It is unambiguous and distinguishes from sibling list tools for other content types (e.g., cms_list_articles, cms_list_events) by naming the specific resource.

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 description conveys that this tool lists photo gallery items, which is appropriate when a list of photos is needed. It does not explicitly mention alternatives like cms_get_photo for single photo retrieval, but the context is clear. There is no explicit guidance on when not to use it, so a 4 is given.

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