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

Goes well beyond the readOnly/idempotent annotations: archived entries are NOT filtered out and this is the only way to find one to unarchive; system groups omit the `pages` field entirely rather than returning an empty list; writes to them yield a 409 and should not be attempted. This is exactly the kind of trait an agent could not infer from structure.

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?

Despite its length, the definition is front-loaded with the purpose and every sentence conveys a distinct rule (ordering, archived visibility, system-group omission, 409 behavior, planner routing). No filler or restated structured data.

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, yet the description still usefully explains the return shape (kind PAGE vs GROUP and their fields) precisely to justify the system-group edge case. For a read tool with rich annotations and a full output schema, nothing an agent needs 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 coverage is 100% and the single projectId is already documented, so the schema carries the load. The description nonetheless ties projectId to downstream usage (planner reads use 'period + date + this projectId'), adding modest context 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 the structure of a project's tab bar: every page and group, top to bottom, with their ids') and distinguishes itself from the six sibling write tools it names. An agent can tell exactly what this returns without opening the schema.

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 'Call this FIRST' and explains why: every other tool in the group needs a viewId/groupId that only this call provides, then names each dependent sibling. It also routes the planner case to xtiles_get_planner_content and xtiles_create_tiles_from_markdown_in_project_planner.

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