error_counters

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

With no annotations, the description carries the full burden. It transparently declares the [READ] nature, discloses the parsing sources and the truncation behavior when 'truncated' is true. This goes beyond basic schema info and gives users essential behavioral expectations.

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 well-structured with sections for summary, proxy-specific notes, args, and return envelope. Every sentence adds value, and it remains concise while being detailed enough for effective use.

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 no output schema, the description explains the return envelope clearly, including the meaning of 'truncated'. It also covers the argument and proxy-specific behaviors, making it complete for a simple read tool with one optional parameter.

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 sole parameter 'target' has zero schema description coverage, but the description compensates fully by explaining it as 'Proxy target name from config; omit for the default.' This provides clear meaning and default behavior that the schema lacks.

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?

Description clearly states it provides per-service request/status-code counters and even distinguishes itself by noting it feeds error_rate_rca. The verb is specific and the resource (service counters) is precisely defined, also covering proxy-specific differences.

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 usage context (feeds error_rate_rca) and explains proxy-specific capabilities/limitations (traefik per-code, haproxy per-class, caddy no per-route counters). However, it does not explicitly state when not to use it or name alternative tools like traffic_stats, so it falls short of full explicit guidance.

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