Frida MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions that the tool is 'very powerful but heavy,' which hints at performance impact, but doesn't specify critical behaviors like whether it requires specific permissions, if it's destructive (e.g., alters execution), what the output format is, or any rate limits. This leaves significant gaps for an agent to understand how to use it safely and effectively.

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 extremely concise and front-loaded, consisting of just one sentence: 'Trace execution at instruction/block level using Stalker. Very powerful but heavy.' Every word earns its place by conveying purpose and a key behavioral trait without any waste or redundancy.

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 low-level tracing tool with no annotations and no output schema, the description is incomplete. It lacks details on what the tool returns, how to interpret results, potential side effects (e.g., performance degradation), or error conditions. For a powerful tool like this, more context is needed to guide an agent effectively, especially without structured fields to fill the gaps.

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 schema description coverage is 75%, with three of four parameters having descriptions in the schema (thread_id, events, duration). The description adds no additional parameter semantics beyond what's in the schema, such as explaining the 'session_id' (which lacks a schema description) or providing examples for the 'events' array. Since the schema does most of the work, the baseline score of 3 is appropriate, but the description doesn't compensate for the 25% coverage gap.

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: 'Trace execution at instruction/block level using Stalker.' It specifies the verb ('trace') and resource ('execution'), and distinguishes it from the simpler 'frida_trace' sibling tool by emphasizing its power and heaviness. However, it doesn't explicitly differentiate from all other sibling tools like 'frida_hook_function' or 'frida_intercept_method' that might also involve tracing.

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 some implied usage guidance by noting it's 'very powerful but heavy,' suggesting it should be used for detailed tracing when performance overhead is acceptable. However, it doesn't explicitly state when to use this tool versus alternatives like 'frida_trace' (which likely offers lighter tracing) or other debugging tools in the sibling list, 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.