tail_app_log

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely new behavior: the environment prerequisite that the desktop app must be installed and running with a specific licence tier, the returned fields, and the staleness rule (logs older than one hour are flagged with a caveat about an earlier session). That is exactly the context annotations cannot supply.

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 critical blocker (tool runs in an uninstalled app) is front-loaded, which is the right ordering. However, the licence/app requirement is stated twice (the install block and the closing sentence), and the install URL plus activation instructions add bulk that is only marginally actionable for an agent.

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?

With no output schema, the description still explains the return fields and the staleness signal, plus prerequisites and sibling routing. An agent has everything needed to decide whether to call it and to interpret the result.

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% for the single 'lines' parameter, so the schema already documents its meaning and default. The description adds nothing about the parameter, which is the expected baseline when the schema does the heavy lifting.

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+resource ('Return the last lines of the app's own log file') and enumerates the shape of what comes back ('present', 'age_s', 'stale: true' with a note). It also distinguishes itself from the log-related siblings v9_tail_log and backtest_status, so an agent can select it without opening any 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?

Gives an explicit positive trigger ('Use it to diagnose an app error') and names the two alternatives with the exact conditions that select them ('For a batch scanner run use v9_tail_log; for a graph run use backtest_status'). The prerequisite (app installed, open, Atelier or Portfolio licence) is stated, leaving nothing material to inference.

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