IT Tools MCP Server

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

Annotations provide readOnlyHint=false (implying it's not a read-only operation, though this seems odd for an identification tool), but the description adds no behavioral context beyond the method. It doesn't clarify if this is a pure analysis (non-destructive), what permissions or data it requires, or potential limitations (e.g., accuracy with partial headers). No contradiction with annotations exists, but the description offers minimal value beyond the annotations.

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 without unnecessary words. It directly states what the tool does and how, with zero waste or redundancy, making it easy to parse quickly.

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 tool's moderate complexity (file type analysis), lack of output schema, and annotations with readOnlyHint=false (which might be misleading), the description is adequate but incomplete. It covers the basic purpose and method but misses usage context, behavioral details (e.g., output format, error handling), and differentiation from siblings, leaving gaps for an agent to infer correctly.

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%, with clear descriptions for both parameters ('data' as hex/base64 file header, 'format' as input data format). The description mentions 'magic numbers/file signatures', which aligns with the 'data' parameter but adds no extra semantic detail beyond what the schema provides. This meets the baseline for high schema coverage.

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 tool's purpose: 'Identify file type based on magic numbers/file signatures'. It specifies the verb ('identify') and resource ('file type'), and the method ('magic numbers/file signatures') provides useful context. However, it doesn't explicitly differentiate from sibling tools like 'lookup_mime_types' or 'validate' tools, which might offer alternative approaches to file type identification.

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. It doesn't mention sibling tools like 'lookup_mime_types' (which might use file extensions) or specify scenarios where magic number analysis is preferred (e.g., for unknown files, security checks). There's also no mention of prerequisites, such as needing file header data rather than a full file.

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