Serena 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 describes the tool's role in workflow sequencing (must be called first) and its dependency on project activation, which adds useful context. However, it lacks details on what the instructions contain, potential errors, or response format, leaving some behavioral aspects unclear.

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 concise and well-structured, using three sentences that each add value: the first states the purpose, the second provides the primary usage rule, and the third covers the exception. There is no redundant or filler content, making it easy to parse and understand 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 simplicity (0 parameters, no annotations, no output schema), the description is largely complete. It explains the purpose, usage rules, and exception handling. However, without an output schema, it could benefit from hinting at what the instructions might include (e.g., project goals, constraints) to better set expectations for the agent.

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?

The tool has 0 parameters, and schema description coverage is 100%, so no parameter information is needed. The description appropriately does not discuss parameters, focusing instead on usage context. A baseline of 4 is applied as it efficiently handles the lack of parameters without unnecessary details.

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 with a specific verb ('Get') and resource ('initial instructions for the current coding project'). It distinguishes itself from sibling tools by focusing on retrieving project-specific instructions rather than performing actions like file manipulation or project activation.

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 explicit usage guidelines: it specifies when to use this tool ('always call this tool before starting to work on any programming task') and when not to use it (exception: 'when a user asks you to activate a project, call `activate_project` first instead'). It names the alternative tool (`activate_project`) for the exception case.

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