JSONPlaceholder MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions retrieval and filtering but lacks details on permissions, rate limits, pagination, or response format. For a read operation with zero annotation coverage, this is a significant gap in transparency.

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 a single, efficient sentence that front-loads the core purpose ('Retrieve albums') and adds necessary qualifiers without waste. Every word earns its place, making it appropriately sized and well-structured.

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 the complexity of a retrieval tool with two parameters, no annotations, and no output schema, the description is incomplete. It doesn't cover behavioral aspects like response format or error handling, and parameter semantics are only partially addressed, failing to provide enough context for reliable 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 schema provides no parameter details. The description adds some meaning by explaining that 'user_id' filters albums and 'album_id' retrieves a specific album, but it doesn't clarify if both can be used together, their data types, or default behaviors, leaving key semantics undocumented.

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 ('Retrieve') and resource ('albums'), and specifies optional filtering capabilities ('by user ID or get a specific album'). However, it doesn't explicitly differentiate from sibling tools like 'get_photos' or 'get_posts' that might also retrieve media-related data, 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 implies usage through the phrase 'optionally filtered by user ID or get a specific album,' suggesting when to use parameters, but it doesn't provide explicit guidance on when to choose this tool over alternatives like 'get_photos' or 'search_posts,' nor does it mention any prerequisites or exclusions.

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