replay_session

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

With no annotations, the description fully carries the behavioral burden. It explicitly discloses read-only constraints ('no model calls, no writes, no re-execution'), defaulting behavior, refusal with verdict 'insufficient_data', and override semantics. This is exemplary transparency beyond the structured 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?

Front-loaded with the core purpose, followed by safety and parameter behavior. Every sentence adds useful information, and the dense but organized structure avoids waste.

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?

For a 4-parameter tool with no annotations and an output schema, the description covers purpose, safety, defaults, failure behavior, and parameter semantics completely. Nothing an agent needs to invoke it correctly is missing.

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%, and the description compensates fully: it explains session_id's default, mechanisms' default values and subset usage, and min_turns/min_tool_calls overrides with PRD context. Every parameter receives meaningful semantic clarification.

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?

States a specific verb ('Reproduce'), precise resource ('one captured session's tool calls'), and measurable outcome ('report the real tool-result token reduction'). It distinguishes itself from sibling replay tools by scoping to a single session and compression mechanisms, so an agent can tell what it does without opening the schema.

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?

Provides clear context: which session is used by default, how to isolate a mechanism, and how threshold overrides work. It does not explicitly name sibling alternatives or state when not to use this tool, but the usage context is specific enough to guide selection.

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