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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds a genuinely useful behavioral note beyond the annotations: it needs 'the user's Cotlet API key with access to this app,' an auth prerequisite an agent must satisfy before calling.

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?

Front-loads the resource and its purpose, then adds the ID usage and auth note. The 'Perfect Venue:' prefix is minor redundancy with the title, but overall it is tight and each sentence carries information.

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 no output schema, the description usefully states what is returned (spaces with their IDs) and why, plus the auth requirement. It omits return shape details and pagination behavior, but for a single-optional-param read tool with full annotation coverage this is largely complete.

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%, and the schema fully documents the single optional venue_id parameter, so the description need not repeat it. The phrase 'your venue' loosely implies venue scoping but adds no syntax or format detail beyond the schema; baseline 3 applies when the schema carries the load.

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 clear resource and result: 'The spaces of your venue with their IDs,' explaining they come from Settings, Spaces. An agent can tell this apart from siblings like list_events or get_event without opening a schema. It stops short of a crisp verb-first phrasing but the purpose is unambiguous.

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?

Gives concrete usage ('Use it to name the room a guest asked for') and cross-references the sibling tools that consume the returned IDs (update_event, create_lead), which implies the workflow context. It does not name an explicit alternative or when-not condition, so it falls short of a 5.

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