Shows blocking chains and lock waits using performance_schema.data_locks or innodb_locks, returning empty when no sessions are waiting.
Blocking chains: performance_schema.data_locks (8.0+) or innodb_locks (<8.0.18). Empty if nobody is waiting.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses version-specific data sources (8.0+ vs <8.0.18) and the empty result when nobody is waiting, which is useful. However, it does not mention that the tool is read-only or any side effects, and the output format is left to the output schema.
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, concise sentence that leads with the key concept ('Blocking chains') and includes essential technical details. It is not verbose, but the phrasing is slightly cryptic and could be more explicit about the action.
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 that there are no parameters and an output schema exists, the description is reasonably complete. It provides version-specific context and the empty-result behavior. It does not explain the output structure, but that is covered by the output schema. It lacks mention of read-only nature, but that is minor.
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 zero parameters, so the baseline is 4. The description does not need to explain parameters, and the schema coverage is 100% (trivially). No additional parameter information is required.
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 mentions 'Blocking chains' and the underlying tables, but does not explicitly state the action (e.g., 'lists', 'shows'). It is not a tautology, but the purpose is implied rather than clearly stated. It distinguishes from siblings by topic, but lacks a clear verb-resource structure.
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?
No guidance is provided on when to use this tool versus alternatives like mysql_innodb_trx or mysql_wait_events. The description does not mention any conditions that would select this tool over others, nor any exclusions. Usage context is solely implied by the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.