Read a host's photo library

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

With no annotations, the description carries the full burden and does well: it discloses read-only behavior, a 50-item cap, and the ownership constraint. It does not cover return format, pagination, or error cases, but the core behavioral profile is clearly stated.

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 sentences, front-loaded with the core action and scope, with the read-only constraint immediately following. No wasted words.

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 simple one-parameter, read-only list tool with no output schema, the description provides everything an agent needs to select and call it correctly: purpose, scope, limit, read-only nature, and where write operations live.

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 host_id parameter is fully documented there. The description adds meaningful extra semantics by requiring that the host be one 'you own', which is not encoded in 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 ('List photos'), scopes it to 'one host you own', and adds a clear boundary ('read-only; uploads and deletion require the website'). It is easily distinguishable from siblings like list_hosts, get_host, or chat_with_host.

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 tells the agent when this tool applies (listing photos for a host you own) and when it does not (uploads and deletion, which require the website). No other MCP sibling overlaps with this read-only photo listing, so no further alternatives are needed.

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