Readwise MCP HTTP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states this is a creation operation ('Create a new highlight') and mentions the return value, but lacks details on permissions, side effects, error conditions, or rate limits. For a mutation tool with zero annotation coverage, this is insufficient.

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 is well-structured and front-loaded with the core purpose. Each sentence adds value: the first states the action, the second covers required parameters, the third optional ones, and the fourth the return. It's efficient with minimal waste, though slightly verbose for such a simple tool.

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?

Given a mutation tool with no annotations, 0% schema coverage, but an output schema exists, the description is moderately complete. It covers parameters and return value, but lacks behavioral context (e.g., auth needs, error handling). The output schema reduces the need to explain returns, but more guidance is needed for safe use.

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 0%, so the description must compensate. It effectively explains all 4 parameters: 'text' and 'book_id' as required, and 'note' and 'tags' as optional. This adds crucial meaning beyond the bare schema, though it doesn't specify formats or constraints (e.g., text length, tag structure).

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 action ('Create a new highlight') and resource ('on a book'), which is specific and unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'tag_highlight' or 'update_highlight', which also involve highlight manipulation, so it doesn't reach the highest score.

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 provides no guidance on when to use this tool versus alternatives like 'tag_highlight' or 'update_highlight'. It mentions required and optional parameters but doesn't specify use cases, prerequisites, or exclusions, leaving the agent to infer usage from context alone.

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